NJDOT Route 78 Rockfall Mitigation

Project Description

As part of an effort by the New Jersey Department of Transportation (NJDOT) to address concerns over potential impact to endangered northern long eared bat (NLEB) and Indiana bat habitat, Paul Carpenter Associates, Inc. (PCA) was contracted to document existing noise and vibration levels as well as predict noise and vibration levels generated by necessary construction including deforestation and explosive rock blasting activities.

A recent bat acoustic survey performed for the NJDOT found that NLEB habitat may exist within the project study area. An inactive rail tunnel in close proximity to project-related activities had been documented in the past as an endangered NLEB hibernaculum. PCA's analysis components included:

• Documentation of existing noise and vibration levels throughout the study area
• Discussion of noise and vibration modeling methodology and procedures
• Noise and vibration prediction modeling results associated with construction phases
• Discussion of potential effects on endangered NLEB habitat

Background noise and vibration monitoring was performed in six locations throughout the project study area including within the inactive tunnel that had been documented as a hibernaculum in the past. Additional noise levels were documented in the vicinity of the bat acoustic survey. Noise prediction modeling was performed using SoundPLAN modelling software. Noise and vibration levels related to construction activities were predicted at both portals of the inactive tunnel and within the surrounding area.

All noise levels resulting from necessary construction activities, including rock blasting, were predicted to comply with the acoustic requirements established by the United States Fish and Wildlife Service (FWS). In addition, vibration levels associated with blasting were not predicted to exceed levels that would damage the habitat located within the study area.